tests: lib: devicetree: api: Add test cases for DT_CHILD_BY_REG_ADDR

Introduce test cases to the devicetree API test suite for
DT_CHILD_BY_REG_ADDR and DT_INST_CHILD_BY_REG_ADDR.

Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>

Author: pdgendt

dts/bindings/test/vnd,child-bindings.yaml

@@ -10,6 +10,9 @@ include: [base.yaml]
 child-binding:
   description: Test child binding
   properties:
+    reg:
+      type: array
+      required: true
     val:
       type: int
       required: true

tests/lib/devicetree/api/app.overlay

@@ -650,16 +650,21 @@
 		/* there should only be one of these */
 		test_children: test-children {
 			compatible = "vnd,child-bindings";
+			#address-cells = <1>;
+			#size-cells = <0>;
 
-			test_child_a: child-a {
+			test_child_a: child@a {
+				reg = <0xa>;
 				val = <0>;
 				status = "okay";
 			};
-			test_child_b: child-b {
+			test_child_b: child@b {
+				reg = <0xb>;
 				val = <1>;
 				status = "okay";
 			};
-			test_child_c: child-c {
+			test_child_c: child@c {
+				reg = <0xc>;
 				val = <2>;
 				status = "disabled";
 			};

tests/lib/devicetree/api/src/main.c

@@ -2514,6 +2514,26 @@ ZTEST(devicetree_api, test_children)
 	zassert_equal(DT_PROP(DT_INST_CHILD(0, child_a), val), 0, "");
 	zassert_equal(DT_PROP(DT_INST_CHILD(0, child_b), val), 1, "");
 	zassert_equal(DT_PROP(DT_INST_CHILD(0, child_c), val), 2, "");
+
+	zassert_equal(DT_PROP(DT_CHILD_BY_REG_ADDR(DT_NODELABEL(test_children), 0, 0xa),
+			      val), 0, "");
+	zassert_equal(DT_PROP(DT_CHILD_BY_REG_ADDR(DT_NODELABEL(test_children), 0, 10),
+			      val), 0, "");
+	zassert_equal(DT_PROP(DT_CHILD_BY_REG_ADDR(DT_NODELABEL(test_children), 0, 0xb),
+			      val), 1, "");
+	zassert_equal(DT_PROP(DT_CHILD_BY_REG_ADDR(DT_NODELABEL(test_children), 0, 11),
+			      val), 1, "");
+	zassert_equal(DT_PROP(DT_CHILD_BY_REG_ADDR(DT_NODELABEL(test_children), 0, 0xc),
+			      val), 2, "");
+	zassert_equal(DT_PROP(DT_CHILD_BY_REG_ADDR(DT_NODELABEL(test_children), 0, 12),
+			      val), 2, "");
+
+	zassert_equal(DT_PROP(DT_INST_CHILD_BY_REG_ADDR(0, 0, 0xa), val), 0, "");
+	zassert_equal(DT_PROP(DT_INST_CHILD_BY_REG_ADDR(0, 0, 10), val), 0, "");
+	zassert_equal(DT_PROP(DT_INST_CHILD_BY_REG_ADDR(0, 0, 0xb), val), 1, "");
+	zassert_equal(DT_PROP(DT_INST_CHILD_BY_REG_ADDR(0, 0, 11), val), 1, "");
+	zassert_equal(DT_PROP(DT_INST_CHILD_BY_REG_ADDR(0, 0, 0xc), val), 2, "");
+	zassert_equal(DT_PROP(DT_INST_CHILD_BY_REG_ADDR(0, 0, 12), val), 2, "");
 }
 
 #undef DT_DRV_COMPAT